Twin Falls, Idaho – Three people have been killed and at least five others wounded after a gunman opened fire at an In-N-Out Burger restaurant in the US state of Idaho.

The gunman was among the dead following the attack in Twin Falls on Saturday afternoon, Chief of Police Matthew Hicks said.

“We believe the threat to the community is over,” Hicks said, adding that the toll was unclear and relatives were still being notified.

“It was a very chaotic scene,” he added.

A witness, Lane Koehn, said he was at a stoplight near the restaurant when he saw someone armed with an AR-style rifle exit the drive-through and then be fired upon by a man with a pistol.

He also saw an employee drag a woman with a gunshot wound to the chest to safety, where they waited for paramedics.

“She was pretty bad off, but I don’t know. I hope she made it,” Koehn said.

City spokesperson Josh Palmer said investigators believed there was one attacker and were working to identify him and determine whether others were involved.

Idaho Senator Mike Crapo said he was “grateful for the swift response of Idaho’s first responders”. (Al Jazeera, excluding headline)

•PHOTO: Image captured from video by a witness shows the scene of a shooting that started at an In-N-Out Burger restaurant [Kevin Bell Jr/AP]